public class Demo01 {
    public static void main(String[] args) {
        //声明变量，语法，变量的类型 空格 数量名
        int a;
        a = 100;
        //给变量赋值
        System.out.println(a);
        //改变变量a 的值
        a = 200;
        System.out.println(a);

        //声明变量，同时给变量赋值
        int b = 500;
        System.out.println("b的值为:" + b);
        System.out.println("a+b="+(a+b));

        //声明多个变量
        int d,e,f = 10;
        d = 11;
        e = 12;
        System.out.println(d);
        System.out.println(f);
        System.out.println(e);

    }
}
